Artificial muscles lift heavy loads

Human-like artificial muscles that can extend to five times their original length while lifting loads 80 times their own weight have been developed by researchers in Singapore. Made from polymers, the artificial muscles mimic the operation of their natural counterparts by contracting and expanding rapidly in response to electrical stimuli. This development is a first for robotics and could pave the way towards a new generation of more efficient, greener and cheaper robots.

The core of the breakthrough comes in the use of dielectric elastomers to form the muscles. In theory, such materials can stretch over 10 times their original length without breaking – enabling them to undertake a range of operations while still carrying heavy loads of many times their own weight. This is unlike today's artificial muscles that are based on hydraulic designs and only capable of lifting loads up to half of their own weight.

"Our materials mimic human muscle, responding quickly to electrical impulses, instead of slowly [like] mechanisms driven by hydraulics," says lead researcher Adrian Koh, of the National University of Singapore, adding that robots with their artificial muscles would move smoothly, unlike their hydraulic counterparts. "Robots equipped with such muscles will be able to function in a more human-like manner – and outperform humans in strength."

Energy harvesting

The muscles also have another important potential application, according to the team. While originally designed to convert electrical energy into mechanical energy, they can also work the other way by generating and storing energy harvested from mechanical movements. According to Koh, a 10-kg muscle-based "soft generator" would be capable of generating electrical energy at the same rate as a one-tonne electrical turbine. In terms of storage, the artificial muscle acts much like a capacitor that is able to reach full capacity very quickly, offering rapid charge times.

As the polymer material is comparatively inexpensive, robots made with these artificial muscles should be much cheaper than those using existing alternatives. Indeed, Koh says that an artificial muscle would cost about 5% of the price of a comparable hydraulic system. The muscles also have the potential to use much less energy than hydraulic systems. As a result, Koh believes that muscle-based robots could become popular consumer products, much like tablets and smartphones are today.

The artificial muscles could have many other potential applications beyond just robotics. For example, Koh says that the technology could be used to create a new generation of more efficient cranes.

Fully soft machines

Commenting on the research, Robert Shepherd at Cornell University says "[This] work on electrically addressable artificial muscles is a big step forward to creating fully soft machines that can operate quickly and with enough strength to perform useful tasks."

Looking to the future, the researchers are continuing to improve their robotic muscles: their next goal is to develop a muscle that can operate repeatedly over a million cycles. In three to five years, the team expects to be able to integrate the muscles into a fully functional robotic arm that is capable of performing such tasks as picking up and accurately repositioning loads. The arm will even be able to take part in an arm-wrestling contest with a human being, Koh says, adding: "We, of course, hope our arm will win!"

About the author

Ian Randall is a science writer based in New Zealand

9 comments

This is a science board, right?

So why is there stuff like this (and this isn't the only article committing this sin)."According to Koh, a 10-kg muscle-based "soft generator" would be capable of generating electrical energy at the same rate as a one-tonne electrical turbine."

OK, how much is that? A one ton turbine made in 1890? Or the kilowatts made by the ones that run on missle exhaust gas presently, yet only weigh a couple pounds.

How many joules out? How many foot-pounds in? Or whatever units you prefer - metric is fine, and widely used too. But real numbers please.

For example, on some sites, you read breathless click-bait headlines that some solar tech has had it's efficiency doubled - all the way to half what the panels that have been on my roof for decades already have...grow up, and report science, not press release dumbed down stuff - what audience do you really want here? This stuff just turns off those who know even pre university science, much less the real knowledgeable.

There is a point here.

So why is there stuff like this (and this isn't the only article committing this sin)."According to Koh, a 10-kg muscle-based "soft generator" would be capable of generating electrical energy at the same rate as a one-tonne electrical turbine."

OK, how much is that? A one ton turbine made in 1890? Or the kilowatts made by the ones that run on missle exhaust gas presently, yet only weigh a couple pounds.

How many joules out? How many foot-pounds in? Or whatever units you prefer - metric is fine, and widely used too. But real numbers please.

For example, on some sites, you read breathless click-bait headlines that some solar tech has had it's efficiency doubled - all the way to half what the panels that have been on my roof for decades already have...grow up, and report science, not press release dumbed down stuff - what audience do you really want here? This stuff just turns off those who know even pre university science, much less the real knowledgeable.

science writing

>>"According to Koh, a 10-kg muscle-based "soft generator" would be capable of generating electrical energy at the same rate as a one-tonne electrical turbine."

>>OK, how much is that? A one ton turbine made in 1890? Or the kilowatts made by the ones that run on missle exhaust gas presently, yet only weigh a couple pounds.

All fair points albeit made in quite a feisty way. Surely however there are no absolutes in science writing, only alternative methodologies with varying degrees of effectiveness in engaging their intended audiences toward one or more goals.

Taken to extremes, if we were to assume some idealised methodology (let's have it please) that suits all audiences at all times, another problem seems likely to emerge : human audiences would be unlikely to have sufficient time or energy to properly assimilate all the information, even if robots might.That's not to say science writing for humans can't or shouldn't improve.

My recommendation would be for all articles to quote their source references in the standard scientific way. In that way, the interested reader can dig deeper if they want to.

that it was Koh's interviewer and Koh himself who perhaps needed to up the ante i.e.

- - - - “Our novel muscles are not just strong and responsive. Their movements produce a by-product -- energy. As the muscles contract and expand, they are capable of converting mechanical energy into electrical energy. Due to the nature of this material, it is capable of packing a large amount of energy in a small package. We calculated that if one were to build an electrical generator from these soft materials, a 10kg system is capable of producing the same amount of energy of a 1-ton electrical turbine” Dr Koh said - - - -

Another discussion has done quite well at dissecting the whole matter somewhat further :

modern science journalism

My girlfriend, who's studying for a masters in science has written :

"Modern science journalism is paradox because normally a journalist's role is to investigate and report but [currently] the heavy reliance on internet embargo information subsidies used by science journalists is contrary to their role - they are often merely passing information on."

In short then, perhaps modern science journalists should make more effort to always offer a critique of their primary resource data in order to raise the quality of debate.

What's important?

In spite of all of the criticisms offered about the specifics of what is or isn't said in the article, it delivers information that layperson idiots, such as yours truly, can understand and appreciate.

The development reported on is a terrific one, and I'm betting that it's going to have a very large number of applications

In spite of all of the criticisms offered about the specifics of what is or isn't said in the article, it delivers information that layperson idiots, such as yours truly, can understand and appreciate.

The development reported on is a terrific one, and I'm betting that it's going to have a very large number of applications

So why is there stuff like this (and this isn't the only article committing this sin)."According to Koh, a 10-kg muscle-based "soft generator" would be capable of generating electrical energy at the same rate as a one-tonne electrical turbine."

OK, how much is that? A one ton turbine made in 1890? Or the kilowatts made by the ones that run on missle exhaust gas presently, yet only weigh a couple pounds.

How many joules out? How many foot-pounds in? Or whatever units you prefer - metric is fine, and widely used too. But real numbers please.

For example, on some sites, you read breathless click-bait headlines that some solar tech has had it's efficiency doubled - all the way to half what the panels that have been on my roof for decades already have...grow up, and report science, not press release dumbed down stuff - what audience do you really want here? This stuff just turns off those who know even pre university science, much less the real knowledgeable.

I think we needa be able to reach a broad range of audiences, including people with little or no knowledge of physics.Yet at the same time I agree that there was not really enough specifics about the muscle, like how dense it is. I mean if the muscle is ridiculously light and fairly big, then even if it can lift 10 times its own weight thats not really going to be much of any use in robots where we have a size limit.